Water cooled stoker



July 4, 1933.

J. S. BENNETT WATER COOLED STOKER Filed Oct. 11,. 1923 3 Sheets-Sheet lI J. S. BENNETT WATER COOLED STOKER July 4, 1933.

Filed Oct. 11, 1929 3 Sheets-Sheet 2 July 4, 1933. J. s. BENNETT WATERCOOLED STOKER 3 Sheets-Sheet 3 Filed Oct. 11, 1929 Patented July 4, 1933UNITED STATES PATENT OFFICE I JOSEPH S. BENNETT, OE PHILADELPHIA,PENNSYLVANIA, ASSIGNOIL TO AMERICAN ENGINEERING COMPANY, OFPHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA WATER GOOLEDSTOKER Application filed October 11, 1929. Serial No. 398,924.

This invention relates to a water-cooled stoker furnace.

An important object of the invention is the provision of a stokerarrangement permitting cooling ofthe tuyeres or of the tuyeres andretort walls as desired, thus increasing the life of the various stokerparts affected by the increasing tendency to use of highly pre-heatedair therein.

A further object of the invention is to provide a construction of thisnature which will permit the cooling to be extended to the overfeedsection.

A still further object of the invention is to provide a construction ofthis character which, if so desired, may be extended to include theadjacent wall of the crusher pit.

A further object of the invention is to provide a structure of thischaracter which may be employed to provide cooling of any or all ofthese sections.

A still further object of the invention is the production of a structureof this character which may be incorporated in a stoker furnace withoutmaterially modifying the construction thereof.

A further object of the invention is to provide a stoker structurewherein the entire area of the stoker body and furnace walls within thefire zone is Water-cooled.

A still further and more specific object of the invention is to providea structure permitting cooling of the pushers and partition platesthereof.

These and other objects I attain by the construction shown in theaccompanying drawings wherein, for the purpose of illustration, I haveshown a preferred embodiment of my invention and wherein:

Fig. 1 is a vertical sectional view through a stoker furnace embodyingwater-cooling of the portions thereof lying'within the fire zone and ofthe crusher pit wall;

Fig. 2 is a section on line 2-2 of Fig. 1;

Fig. 3 is a section on line 33 of Fig. 1',

Fig. 4 is a vertical longitudinal sectional view through the stoker ofFig. 1;

Fig. 5 is a similar section through a slightly modified stokerconstruction;

Fig. 6 is an elevation of a stolrer section constructed in accordancewith the showing ing of the under-feed section where such these sectionsare cooled and in which a header 13 is arranged at the front wall and aheader 14 at the bottom of the crusher pit wall, these headers beingconnected by tubes 15 which extend along the under-feed section,preferably in contact with the tuyeres thereof as more particularlyshown in Fig. 3.

At the over-feed section 11 the over-feed pusher 16 is preferablyincreased in depth so that an'increased arc in bending the tubes, asindicated at 17, may be provided. From the bend 17 these tubes extenddownwardly along the front pusher pit wall and connect to the header 14.In a construction of this character any of the tuyre and retort wallcooling arrangements of Figs. 4 and 7 to 11 may be provided. Such aconstruction is, however, disadvantageous to a certain extent in that itdoes not permit of cooling of the sections 12a of the crusher pit wallwhich are in alignment with the retort. Where cooling of these sectionsis desired the arrangement of Figs. 5 and 6 is employed. In thesefigures an intermediate header 18 is disposed between the headers 13 and'14 and at the top of the crusher pit wall. The tubes 15 are dividedinto sections 150, and 15b of which the sections 15a extend from'thefront wall to the header 18 and the sections 155 from the header 18 tothe header 14, the firstnamed sections cooling the tuyeres, and, ifdesired, the retort walls, While the last-named sections cool thecrusher pit wall in alignment with the tuyeres.

So far the construction described provides the same cooling as thatprovided by the construction originally described. However, header 18may be connected with the header 14; by additional tubes 19 underlyingthe retort section which serve to cool those portions of the crusher pitwall in alignment with the retort sections. If desired, in aconstruction of the latter character the cooling may be confined to thetuyeres and the retort walls by omitting header 14 and pipe sections15?) and 19. Similarly the cooling may be confined to the crusher pitwall by omitting the header 13 and pipe sections 15a. The headers 13 and14 may be either supplied with cooling fluid from a separate source or,as illustrated, be interconnected with the circulation system of theboiler through conduits 21 and 22. This arrangement may be employedwithout any material modification of the stoker construction and willresult in. a considerable saving due to the extension of the life of theparts aflected where the stoker is employed with highly pre-heated air.It may, of course, be previded in any stoker construction.

In many instances it may prove desirable to cool the pushers 23,partition plates 24: and the over-feed section 16 of the furnace. Thisis accomplished by making each of these sections in the form of achamber having fluid feed and return pipes 25 and 26 communicatingtherewith. The feed and return pipes leading to the over-feed section 16and the pushers will, of necessity, include flexible sections sincethese parts are reciprocated through the usual mechanism generallydesignated at 27. Those leading to the partitions 24 may, however, be inthe form of rigid tubes.

It will be noted that the lower portion of the front wall will be cooledby fluid from header 13 and by the vertically-extending conduits21. Itwill, therefore, be obvious that by combining with the featureshereinbefore described a side wall structure such as set forth in myprior application, Serial No. 314,098, filed October22, 1928, for waterwall and air cooled refractory construction the entire fire zone may bewater-cooled.

The cooling structure described in said application includes headers 28and 29 located adjacent the rear and front walls of the furnace andconnected by inclined tubes 30 built into the side walls of the furnace,these tubes covering the entire fire zone of the furnace side wall.Circulation is established through the headers 28 and 29 and tubes 30 byconnecting the same with the circulatory system of the boiler throughconduits 31 and In Figs. 3 and 7 to 13 inclusive T have illustratedvarious arrangements of the tubes 15 which may be conveniently employed.In the usual practice these tubes will be covered by blocks 33 which maybe either of the U type as illustrated in Figs. 3 and 7 to 11 inclusiveor of the T type as illustrated in Fig. 12. It will be noted, however,from an inspection of Fig. 13 that it is not necessary that these tubesbe covered, as they may actually form the retort side walls and thetuyere section as suggested in this figure.

Since the structure illustrated is capable of a considerable range ofchange and modi- I fication without in any manner departing from thespirit of my invention, I do not wish to be understood as limitingmyself thereto except as hereinafter claimed.

1 claim 1. In combination with a stoker furnace having a crusher pit, afront wall and the usual under-feed and over-feed sections extendingfrom the front wall to the upper end of the crusher pit wall, means forfluid cooling the tuyere sections and said crusher pit wall includingfluid circulation tubes extending from said front wall to the lower endof said crusher pit wall, said tubes being formed in sections, therebeing a header at the upper end of the crusher pit wall with whichadjacent ends of the sections communicate.

2. In combination with a stoker furnace having a crusher pit, a frontwall and the usual under-feed and over-feed sections extending from thefront wall to the upper end of the crusher pit wall, means for fluidcooling the tuyere sections and said crusher pit wall including fluidcirculation tubes extending from said front wall to the lower end ofsaid crusher pit-wall, said tubes being formed in sections, there beinga header at the upper end of the crusher pit wall with which adjacentends of the sections communicate and headers at the front wall and lowerend of the crusher pit wall with which the remaining ends of thesections communicate.

3. In combination with a stoker furnace having a crusher pit, a frontwall and the usual under-feed and over-feed sections extending from thefront wall to the upper end of the crusher pit wall, means for fluidcooling the tuyere sections and said crusher pit wall including fluidcirculation tubes extending from said front wall to the lower end ofsaid crusher pit wall, said tubes being formed in sections, there beinga header at the upper end of the crusher pit wall with which adjacentends of the sections communicate and headers at the front wall and lowerend of' the crusher pit wall with which the remaining ends of thesectionscommunicate, the last-named headers being connected in [thecirculation system of the boiler.

4. A stoker furnace including retort walls, said retort walls comprisingfluid circula tion tubes and refractory elements in heatconductiverelation with said tubes and forming the effective wall surfaces, otherfluid circulation tubes extending longitudinally between the upper endsof said retort walls, tuyere elements in heatconductive relation withsaid last-named tubes, and means for circulating fluid through saidtubes.

' tuyeres and said 5. A stoker furnace including retort walls, saidretort walls comprising,fluid circulation tubes, other fluid circulationtubes extending longitudinally between the upper ends of said retortwalls and means for circulating fluid through said tubes, protectiveblock facing the retort walls and tuyeres seated upon the last-namedtubes.

6. In a stoker furnace, the. combination with an inclined gratestructure consisting of alternately arranged longitudinally extendingtuyeres and retorts, of an ash pit terminating the lower end of thegrate, fluid circulation tubes in cooling and protective relation to thetuyeres and aligned portions of the wall of said pit, and other fluidcirculation tubes in corresponding relation to those parts of the saidwall in alignment with said retorts.

. 7. A mechanical stoker comprising an inclined grate consisting ofalternately arranged longitudinally extending tuyeres and retorts,fuel-feeding pushers in the bottoms of said retorts, and fluid coolingmeans in cooling and protective relation both to the pushers.

8. In a stoker furnace, a grate comprising alternated tuyeres andretorts, means for advancing fuel in the retorts, an ash pit terminatingsaid grate, and walls surrounding said grate and pit, and fluid coolingmeans -in cooling and protective relation to said walls, tuyeres,retorts, fuel advancing means, and with the walls of said pit andforming a completely fluid cooled enclosure embracing the entire firezone of said furnace.

9L In a mechanical stoker, a plurality of parallel tubes arranged ingroups and defining a plurality of spaced retorts, protective blockssecured to the tubes and forming the wall facings of said retorts, andtuyeres also associated with the tubes and'bridging the spaces betweensaidfretor'ts.

10. In a mechanical stoker, a plurality of parallel banks of fluidcirculating tubes defining the' walls of spaced retorts, protectiveblocks secured to the tubes and forming the wall facings of the retorts,and tuferes bridging the spaces between the retorts.

1 1. In a mechanical stoker, a plurality of parallel banks of fluidcirculating tubes defining the walls of spaced'retorts, protectiveblocks secured to the tubes and forming the wall facings of the retorts,tuyeresbridging 'the spaces between the retorts, and fluid cooledpushers operative in the bottoms ofsaid retorts. v

12. In an underfeed stoker. furnace, the combination with a boiler, of aseries of inclined tuyeres forming a series of retorts,-

inclined longitudinally toward an ash discharge at the lower ends of theretorts, a transverse water header embodied in cooling and over whichthe ashes discharge, a downtake connection from the boiler feeding waterto said header,-uptakes extending from the header along the tuyeres'incooling relation thereto, and uptake connections from said uptakes tothe boiler.

13. An underfeed furnace comprising a plurality of parallel underfeedretorts which are spaced apart to provide passages for air, means tofeed fuel into the front ends of the retorts. wallsi providing atransverse ash dump in the rear of the retorts, water circulating meanshaving portions mounted above the air passages and sloping downwardlytoward the rear, means associated with said portions to distribute airfrom said passages into the fuel, the lower end of said into the fuel,means to supply water to the lower ends of the tubes, a transverseheader at the front ofthe furnace into which the upper ends of the tubesare connected, and-a row of water wall tubes associated with the frontfurnace wall and connected at their lower ends to said header, saidwater wall tubes being arranged to absorb radiant heat from the furnace.

15. In an underfeed stoker furnace, the combination with a boiler, of aseries of inclined tuyeres forming a-series of retorts, inclinedlongitudinally toward an ash discharge at'the lower ends of the retorts,a transverse water header embodied in cooling relation across the lowerends of the .retorts and over which the ashes discharge, a downtakeconnection from the boiler feeding wa te'r to saidheader, uptakesextendingfrom the header along the tuyeres in cooling rela- I tionthereto, and uptake connections from said uptakes to the boiler, saidtuyeres being of section tapering upwardly to a ridge, with one of saidwater uptakes embodied in cooling relation within the ridge.

. I JOSEPH S. BENNETT.

relation across the lower ends of the retorts

